The present invention relates to fasteners for connecting pipe sections, and more particularly relates to vent cap fasteners for connecting a vent cap to a flue pipe of a furnace or other such combustion system.
One situation in which it is especially desirable to provide a fastener for easily connecting and disconnecting tubular pipe sections is when it is desired to connect a vent cap, for example, a vent cap such as shown in U.S. Pat. No. 3,650,198 to Stone, to a flue pipe of a furnace or other such combustion system. One function of such a vent cap is prevent the influx of rain, foreign objects, and animals, such as birds, into the flue pipe. Therefore, the vent cap must be connected to the flue pipe so that the vent cap can not be easily blown or knocked off of the flue pipe. Furthermore, it is sometimes necessary to remove the vent cap to clean the flue pipe, to perform maintenance functions on the furnace, to install the furnace, or to add or replace component parts of the furnace. Thus, it is particularly desirable to provide a fastener which allows the vent cap to be easily removed from the flue pipe.
Many different kinds of fasteners are known for connecting sections of tubular pipes such as stove pipes and vacuum cleaner hoses. Some pipe sections are connected by fasteners which are welded or bolted to the pipes making it very difficult to connect and disconnect the pipes. Some fasteners are snap type fasteners which make it possible to easily connect the pipes but which make it somewhat difficult to disconnect the pipes. Fasteners which are designed for both easy connection and easy disconnection are usually relatively complex in construction and operation and are relatively expensive to manufacture.